JDMZ28

So yeah I bought an 03 vette, black on black 30,000 miles. Its an auto 2.73 car. It is completely stock. I have friends with ls1 powered f-bodies and I know they respond well to mods but I have a few questions I'd like to hear what you guys think.

What should I dyno stock? About 285? I have an HP tuner and a wideband, how much power should a good tune give me? I'm assuming about 15 whp. A catback should be good for about 10 and a CAI should be 10 also, right?

Can I expect 320hp at the wheels free these three mods? My buddies 00 Z did 323 whp with only a muffler/ lid and free mods at APE before they killed themselves.

AL SS590 M6

A 2.73 a4 car will dyno less than any other combo. You could get the 35hp or not.
But you're starting in the right area. Next would be gears and a converter which won't gain you any power but will make the car way quicker and much more fun to drive.

JDMZ28

thanks for the reply. I think I'm going to start with the cold air intake, maybe port the maf/ TB and tune it. I think that will make a big difference either way. This car has some sick topend already even with the gears, it feels like I bought a healthy one (since I know how random these engines are). I'm trying to keep this one stock appearing, so the catback and intake will probably be the only "visible" mods. I'm hoping and confident a good tune will boost up the midrange. I'm definitely not doing a convertor but I might consider gears in the future however I enjoy the 2.73's as lame as that sounds and they don't feel like they are hurting performance much. Its cool to see how the lighter vette just rips in this cold weather.

I have past experience tuning my LT1 and L67 (3.8 SC). If I remember correctly a near stock LS engine is pretty simple to tune, right? I'm wondering what areas of the timing table need work and what total advance I should shoot for. Isn't WOT a/f suppose to be around 13.0:1? Don't these run rich from the factory? Aren't these engines known for being good about not having KR?

ss.slp.ls1

I would get CAI, headers, cat-back, and 3.73 gears. I have heard of porting the MAF leading to problems, the stock MAF can handle alot of power, I would leave it alone. If you are ever planning on valve train upgrades, I would do them now while you still have low miles. Have fun.

Kraest

Leave the Vette MAF alone.

I made 530rwhp with an untouched one on my 408ci all motor.

Kraest

Catback of your choice (the Borla straight-pipe is around $350 and the cheapest - Won't be too loud with stock cats and X-pipe), Halltech Stinger intake, gears (3.73s), converter (Yank SS3600 or something similar), and eventually some nice headers like the Kooks or LG Motorsports.

JDMZ28

thanks guys. I'm really liking the Corsa systems that might be the ticket. I'll leave the maf alone then.

Kraest

The Corsa is awesome, but very very pricey. I'd look into a used stock C5 Z06 titanium catback for around $300-400.

Mike94ZLT1

I have the Corsa Indy's on my car, I yanked the Z06 Ti's off because I thought they were way too tame. I live in Livonia, I'm not too far away if you want to hear them in person. My car is in storage for another week or two.

AL SS590 M6

Might I ask why? A good converter like the one Mike suggested will give you more accelleration than everything else that you've listed and with no downside in driveability or fuel economy. When I added a Yank ST3500 and a TransGo valve body kit to my 00 Formula I went from a best of 12.96 at 108mph to a 12.15 at 110mph and the mid range acceleration on the street was just crazy instead of lazy.

JDMZ28

Sure I would, I live in northville now I haven't been on here since I sold my TA back in 06 so my info is a little out of date. The Corsa or Borla are what I want for quality and sound, I'm not too concerned about the price.

Any guess what RWHP I'll be making with the catback, tuning (with wideband) and CAI? I would sure hope its over 300